The U.S. military incurred about $38 billion in costs from combat operations against Iran through Aug. 1, while the campaign consumed an estimated one-half to two-thirds of the combined U.S. inventory of four major missile-defense interceptor systems since June 2025. The figures come from a Congressional Budget Office analysis that warns rebuilding the depleted stocks could take at least five years, even if production rates increase.

The estimate covers Patriot, Terminal High Altitude Area Defense, or THAAD, Standard Missile-3 and Standard Missile-6 interceptors. The Pentagon does not disclose the number of interceptors in its inventory, so CBO analysts estimated consumption by comparing reported expenditures with the total number of missiles the Defense Department has purchased. The one-half-to-two-thirds range applies to the combined inventory of those four systems, not to each system individually.

The interceptor expenditure represents the campaign’s largest replacement cost within the munitions total. CBO estimates the Pentagon would need $21.7 billion to replace munitions expended through Aug. 1. Interceptors account for $13.1 billion of that amount, while land-attack cruise missiles account for $7.3 billion and other munitions for $1.2 billion.

The broader $38 billion operating-cost estimate includes expended munitions, equipment losses, increased flying hours, other operations and higher fuel costs. It excludes costs borne by other federal agencies and military operating costs already included in the federal budget. The largest expenses outside munitions were $10.4 billion for increased flying hours, $2.7 billion for fuel and $1.9 billion to replace equipment lost in battle. Those equipment losses included a THAAD radar destroyed by Iran.

The campaign’s first few weeks involved especially large munitions expenditures as U.S. forces defended against Iranian ballistic-missile and drone attacks. The initial phase of Operation Epic Fury involved about 250 tactical aircraft, including roughly 90 aircraft from two carrier strike groups, along with an amphibious ready group. Bombers, airlifters, refueling tankers, other Navy vessels and Army air-defense, aviation and artillery units supported those forces.

The costs are tied to the price and production pace of the interceptors. CBO estimates a unit cost of roughly $4 million for either a Patriot or an SM-6 interceptor, $12 million for a THAAD interceptor and $28 million for a sophisticated SM-3. The analysis says the United States had already used significant quantities of the weapons defending Israel before expending more during Operation Epic Fury.

CBO’s estimate is subject to considerable uncertainty because the Pentagon did not respond to the agency’s requests for information. Analysts instead relied on government databases and public reports. A Defense Department inspector general report separately estimated the operation’s cost at $33.4 billion through June 29, a different time period from the CBO estimate through Aug. 1.

The administration requested $87.6 billion in supplemental funding in June, including $67.1 billion for the Defense Department. Of that request, $42.3 billion was identified as directly related to the conflict, about 10% higher than CBO’s estimate of costs through Aug. 1.

The cost could continue to rise. CBO estimates that each additional month of fighting would cost roughly $2 billion to $3 billion if the intensity remains relatively low, with higher costs possible if operations intensify. The agency also identified the depleted interceptor stocks as a particular concern in a conflict with China, which maintains large numbers of ballistic and cruise missiles.